Stem cell hope for stroke victims

Rebecca Smith in London

Brain damage caused by strokes could be repaired through the use of stem cells in a discovery that may revolutionise treatment, a study has suggested.

Researchers at Imperial College London found that injecting a patient's stem cells into their brain may be able to change the lives of the tens of thousands of people who suffer strokes each year.

Their results have been called "one of the most exciting recent developments in stroke research".

Doctors said the procedure could become routine in 10 years after larger trials are conducted to examine its effectiveness.

Researcher Dr Paul Bentley, from the college's Department of Medicine, said: "Currently, the main form of treatment is an unblocking of the blood vessel, and that only helps one-third of the patients who are treated and only 10 per cent are eligible anyway. So we said, 'What about the other 90 per cent?' "

The team targeted patients who had suffered severe strokes involving a clot in a blood vessel in the middle of the brain. Typically, there is a high mortality rate in these patients and those who survive are often severely disabled, unable to walk, talk, feed or dress themselves. The experimental procedure was carried out on five such patients, aged 40 to 70, all of whom showed improvement over the following six months, and three were living independently.

Advertisement

Dr Madina Kara, a neuroscientist at the Stroke Association, said: "This is one of the most exciting recent developments in stroke research. However, it's still early days in stem cell research, but the findings could lead to new treatments for stroke patients in the future.

"In the UK, someone has a stroke every three and a half minutes, and around 58 per cent of stroke survivors are left with a disability."

The experimental procedure involved harvesting the patient's own bone marrow, which was then sent to a specialist laboratory so specific stem cells, called CD34+, could be selected. The patient then has a wire inserted into the area of the brain damage. Once there, the stem cells are released and the wire retracted. During the trials the whole process took half a day, but it is hoped that with refinement it could be reduced.

It is thought the cells work in two ways: by growing into small blood vessels that allow the brain to grow new nerves and brain tissue surrounding them, and by releasing anti-inflammatory chemicals that encourage tissue repair.

Principal investigator of the study Professor Nagy Habib said: "These are early but exciting data worth pursuing. Scientific evidence from our lab further supports the clinical findings and our aim is to develop a drug, based on the factors secreted by stem cells, that could be stored in the hospital pharmacy so that it is administered to the patient immediately following the diagnosis of stroke in the emergency room. This may diminish the minimum time to therapy and therefore optimise outcome."

However, Professor Robin Lovell-Badge, head of developmental genetics at the National Institute for Medical Research, advised caution over the "small safety trial" involving very few patients. He said the improvements "could be just chance, wishful thinking, or due to the special care these patients may have received".